This colossal 18th-century building is the second largest in Spain after El Escorial and once employed thousands of cigarreras — the women who hand-rolled cigars and inspired Bizet's Carmen. Now home to the University of Seville, the building retains its imposing stone facade, moat, and watchtowers that hint at how seriously Spain took its tobacco monopoly. You can wander freely through the courtyards and corridors during term time, soaking up the grandeur while students rush to lectures around you. The sheer scale of an industrial building given palatial treatment makes this unlike anything else in the city.